The semiconductor industry has been experiencing rapid growth due to continuous improvements in the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). For the most part, this improvement in integration density has come from repeated reductions in minimum feature sizes, which allows more components to be integrated into a given area. However, smaller feature size may lead to more leakage current. As the demand for even smaller electronic devices has grown recently, there is a need for reducing leakage current in semiconductor devices.
The so called Fin field effect transistor (FinFET) device is becoming increasing popular. The FinFET device is fabricated with a thin fin-like structure called a “fin”, extending from a substrate, and a gate provided over (e.g., wrapping around) the fin. The fin structure is made of semiconductor material, typically silicon, and if used as a transistor, has a current channel formed inside. Because the gate wraps around the channel region on three sides, FinFETs provide excellent channel control with small critical dimensions.